Vikings and rodents - all over the place!
Recreation of Newfoundland Viking settlement (photo by Dylan Kereluk)
People and animals have moved around the world much more than we used to think. Recent breakthroughs in archeology and genetics have made it possible to pinpoint ever more accurately where various populations lived and when they lived there. A recent example is the establishment of 1021 AD as the exact year when Norsemen first established a settlement at l’Anse aux Meadows, Newfoundland.
A rare solar storm in 993 left its imprint on the wood that was used to build the timber structures on the l’Anse aux Meadows site. Trees that were growing in 993 AD showed extra carbon in their core growth for that year. Archeologists analyzed wood from three different trees used for construction on the site and simply counted the rings back from the outer ring to the extra carbon ring from 993 AD. They counted 28 rings, meaning the trees had to have been cut down in 1021 AD.
As if that breakthrough wasn’t fascinating enough for Viking enthusiasts, it was soon followed by the publication of a very plausible new theory that it was the Vikings who first settled the Azores Islands in the mid-Atlantic Ocean off the coast of Portugal. Researchers studied samples of lakebed sediments on the Islands and discovered them to be rich in compounds of cow and sheep manure but low in pollen from local trees. Dating of the samples showed them to go back to 700 to 850 AD, well before the settlement of the islands by the Portuguese. It was, of course, the time of the Vikings, who we know kept both cows and sheep.
Here is where the rodents come in. Evolutionary biologists are now able to trace the origins of different mice populations. Mice sneak on board ships and disembark to form new populations all over the world. The biologists found that the mouse population in the Azores today are genetically similar to Icelandic and Greenlandic mice, who in turn are descended from Nordic mice. In short, their ancestors were Viking mice! While not definitive proof that the Vikings were the first to settle the Azores, it certainly adds another layer of plausibility to that theory.
And speaking of rodents, this is the point where I would like to clarify some misconceptions about what is often called the Norway rat. The common brown rat is widespread in the world and is now the dominant rat in Europe and much of North America. If you have ever seen a rat (and they are becoming more and more visible in Canadian cities), it was most likely a so-called Norway rat.
Photo of Norway or Brown Rat by VJAnderson (commons.Wikimedia.org)
Many, many people are under the mistaken impression that the Norway rat originated in Norway. This misconception arose when English biologist John Berkenhout gave the rats the name rattus norvegicus because he mistakenly believed the rats had first arrived in England aboard a Norwegian ship in 1728.
In fact, biologists now believe that the brown rat originated in northern China and Mongolia sometime in the Middle Ages.
To my CNS Norwegian friends who pleaded with me quite a while ago to use this newsletter to correct the grievous and embarrassing misconception that the brown rat originated in Norway, you’re welcome (and sorry it took so long)!